Electronic seaming machine



Jan. 29, 1952 w C, RYKERT 2,583,709

ELECTRONIC SEAMING MACHINE Filed June 15, 1948 5 Sheets-Sheet 1 ATTHNEY Jan. 29, 1952 w. c. RYKERT ELECTRONIC SEAMING MACHINE 5 Sheets-Sheet 2 Filed June l5, 1948 j INVENTOR.

WLLARD QRYKERT TTENE' Jan. 29, 1952 w. c. RYKERT 2,583,709

ELECTRONIC SEMING MACHINE Filed June l5, 1948 5 Sheets-Sheet 5 mw um Im" "WHW 1l IN VEN TOR.

WIL LARD c. RYKERT BE" n ATTENET' `lan. 29, 1952 w C, RYKERT 2,583,709

ELECTRONIC SEAMING MACHINE IN VEN TOR.

wlLLARD c. RYKERT BY I ATTHNEY Patented Jan. 29, V1952 'ELECTRONIC SEAMING MACHINE Willard C. Rykert, Hinsdale, Ill., assignor to Union Special MachineCompany, Chicago, Ill., a corporation of. Illinois 'Applicationkune 15, 1948, Serial No. 33,189

11 Claims. l

This invention relates toapparatus, commonly designated electronic seaming machines, used for the purpose of bonding together, by high frequencyr electric oscillations, sheets or sections of dielectric material. This is done by including. in the seam one or more thermoplastic films or layers rendered adhesive by v'the dielectric -losses therethrough resulting from the generation of an ultra 4high frequency field in the region of the seam, In machines of this character electrodes are engaged with the opposite faces of the sections of' dielectric material constituting the'work to :be united, and relative movement is created betWeen-the-electrodes l and the-sections of material to subject successive increments of the work to a high-frequency field,-thereby producing a bond along-a desired seam line.

y.Heretofore machines of theforegoing character have .been provided withrigid, unyielding rollers, in .closely-spaced relation, and the'materials to be bonded have been fed throughA the bight of the rollers either'by the frictional driving action thereofvor Vthrough the'aid of auxiliary feeding means. `The rollers have served not only asfwork feeding-means ybutas electrodes for the delivery of-the high vfrequency oscillations to thework pieces for the generation ofthe desired heat. The rotary electrodes.andwork-feeding rollers employedv heretofore have been formed, largely of rigid metalso as to serve the dual" functions indicated.

It has been* found necessary in the operation of thernachines, as heretofore constructed, to provide-means forpreventing the actual engagement ofthe electrodes with each other Whenever the high frequency `oscillations have been delivered thereto. It has been found that if the electrodes are permitted to come into direct contact with each other, objectionable arcing will 'occur when they are vseparated as thel work pieces are advanced lbetween' them-or asian incident to the introduction of the work. Such arcing has frequently caused the surfaces of the electrodes to become pitted and unsuitable for further use.

.A primary object, of the-,present invention has been to provide rotary electrodesrof improved construction adapted to deliver lthe desired high frequency oscillations -to the opposite faces of the work pieces-under more favorable conditions than is possible throughv the use `of the rigid rotary electrodes heretoforeemployed.

Toward the foregoing end,fan important lfeature of ,the invention is the provision of rotary electrodes, for machines of the character indicatedl, which have yielding surfaces on elements of good electrical lconductivityadapted toengage the opposite faces of the Work. These elements areradapted to engage the ywork over a greater area than is possible with rigid rollers. The rigid rollers, heretofore employed, have had a relatively thin line contact'with the work, so that the f'leld set up in the dielectric material, at any instant, has been of very limited area. In accordance With the present invention, on theother hand, the flattening -of the peripheriesr of the rotary electrodes has served to increase `theirfarea ofengagement withthe work, so that the highfrequency oscillations are set `up through a portion of the Work having a correspondingly greater area. A condenser of `substantial-area is thus formed by the-parallel faces of the flattened portions of the electrodesand the interposed dielectric material. This gives rise -to` various advantages. It permits the use of a'high frequency 'current of lower voltage, since the heatingl effect of the field set up inthe dielectric material-is maintained atv each pointover a vlonger period of time. A particular point along the line Vof seam may remain in the field during a plurality kof feeding movements of the work-so that .the intensity of the heating action need not be so great. The increased effective-area of the electrodes at any instantalso permits higher seaming speeds to be employed.

Another object of the invention has been to provide a more positive feed for the Work, while retaining the advantages of rotary electrodes. This is accomplished bythe provision of flexible rotary electrodes adjacent to, or positioned between two portions of, a rigid feed roller. The flexible electrode for each roller is formed With a slightly greater outside -diameter than its associated roller, so that as the rigid rollers are urged forcibly against each other, or the opposite faces of. the Work, the flexible electrodes are flattened at their points iofcontact. The arrangement is such, moreover, that-the force required to flatten the flexible electrodes, to the extent permitted by the rigid feed rollers, is relatively small. This makes itpossible vto provide-as muchpressure as desired between the feed'rollers, since these are not brought in contact with portions of the work which are softened by the action of the heat generated by the high-frequency oscillations. The areas of thevwork which `are' heated by the high frequency field are subjected only tothe relatively light squeezing action of the resilient means tending to maintain the circularform of the electrodes. This force, as indicated above, maybe made relatively small. A- quite positive feed may be insured by the friction created between the high pressure feed rollers and the work.

A still further object of the invention has been to provide an arrangement in which objectionable arcing is eliminated even though the electrodes are permitted to come into direct engagement with each other and are then separated while the power is turned on. It has been found that the dielectric material may be fed into and out of the path of the feed rollers and the fiexible electrodes without producing serious arcing difficulties. Apparently this is due in part to the lower voltages permitted and in part to the fact that as the work is fed between the electrodes the latter remain in direct contact with each other until the work has advanced to 'or beyond the plane extending through the axes of the two feed rollers. As the material advances through this plane the electrodes are separated, and a certain amount of arcing takes place, but the interval of time involved is so small that no substantial harm is done. The arc is formed for only an instant. When rigid electrode rollers are employed, on the other hand, the arcing continues for a sufficient period to injure the surfaces of the electrodes.

An additional object of the invention has been to provide electrodes which serve to produce their heating effect more uniformly over the width of the seam. Electrodes as heretofo-re constructed have had a tendency to concentrate a greater portion of the field, and hence the heating effect, at the corners or edges of the rotary electrodes with resultant weakening of the seams at these points. This tendency has been overcome by the provision of flexible electrodes and by providing a special configuration to the periphery of the same. It has been found that the field generated between the improved rotary` electrodes does not have the same tendency to concentrate at the corners or edges as do prior electrodes. The distribution of the field over a broader area, due to the flattening of the work engaging portions, as explained above, apparently contributes largely to this result. The heat being transmitted through the material over a longer period of time, and therefore being of lesser intensity at any given instant, has an opportunity to become more evenly distributed over the width of the seam.

While the invention is applicable to machines for either continuous or intermittent feeding of the work, it is particularly advantageous in relation to machines having an intermittent feed. The intermittent feeding of the work, which is produced, for example, through the rotation of the feed wheels through successive small increments corresponding with stitch lengths, enables the operator to turn the work in relation to the feed rollers and electrodes at times when the rollers are stationary. It been found that work may be turned on a relatively small radius of curvature, at such times, when the intermittent feed action is provided. The formation of seams of small radius is more diilicult when a continuous feed is provided. Moreover, the present invention enables the formation of an uninterrupted seam even though the feed is intermittent. This is not possible when rigid rotary electrodes are employed.

Other objects, features, and advantages of the invention will appear from the detailed description of an illustrative form of the same, which will now be given in conjunction with the accompanying drawings, in which;

Fig. 1 is a view, partly in front elevation and partly in vertical. section through a machine embodying the invention;

Fig. 2 is an end elevation of the machine as viewed from the left in Fig. 1, a cover for the end of the overhanging arm being removed to disclose the interior mechanism;

Fig. 3 is an end elevation of the machine as viewed from the right in Fig. 1, a portion of the frame being broken away to disclose the interior construction and certain of the shafts being shown in section;

Fig. 4 is a bottom view of the machine, a portion of the cover plate for the lower end of the standard being broken away to show the interior mechanism;

Fig. 5 is an enlarged detail View in section along the line 5-5 of Fig. 1;

Fig. 6 is an enlarged detail view, in end clevation with some of the parts broken away, showing the work feeding rollers and the rotary electrodes;

Fig. 7 is a vertical sectional view through the feed rollers and electrodes, taken along the line 1 1 of Fig. 6;

Fig. 8 is a transverse section through one of the electrode bands in the course of formation;

Fig. 9 is a detail view in section through a portion of the periphery of one of the electrodes; and

Fig. 10 is a diagrammatic view showing a suitable electrical circuit employed in the use of the invention.

Referring now to the drawings, the illustrative machine comprises a main frame having a work supporting member I0, a vertical standard II, and an overhanging arm I2 terminating in an enlarged head I3. The work supporting member I0, it will be understood, is adapted to be mounted in a suitable table (not shown) which is preferably adapted to carry the entire electronic seaming apparatus. In the outer end wall of the vertical standard there is mounted, in suitable needle bearings I4, a shaft I5 carrying at its outer end a combined hand wheel and pulley I6 adapted to be connected by a V-belt or the like with any suitable source of power, such as a pulley driven by an electric motor. In axial alignment with the shaft I5 is a shaft I1 having a reduced end I'Ia, adapted to fit into the bore provided at the inner reduced end portion I8 of the shaft I5. Secured to the reduced portion I8 of the shaft is an eccentric I9, preferably having a spherical surface, arranged to cooperate with a strap 20 which is connected by a pitman 2| and a similar strap 22 with a spherical portion of a pin 23 adjustably mounted in an elongated slot 24 in an arm 25. The latter projects from a driving element 26 of a one-way clutch. This clutch is, in general, one of the type shown in the patent to Long et al., No. 1,692,130, granted on November 20, 1928. It will be understood that by adjustment of the pin 23 along the slot 24 the stroke of the arm 25 may be varied and the angle through which driving member 26 of the clutch is oscillated may be correspondingly varied. Operation of the member 26 in a clockwise direction (Fig. 3) will impart a like movement to a driven clutch member 2T secured to a driven shaft 28. This is accomplished through the roller and cam clutch elements illustrated in the Long etal. patent above mentioned. Operation of the driving member 26 in the opposite direction, however, will not impart rotation in that direction to the driven member of the clutch .duetto l.the .action of afstatlomg'y. memberv 29 cooperating, through-similar roller and `cam members, .to .prevent -ieverse rotation. Plate 29 isz-.secured to the encl walloff the .standard :by means-ofeserews30. .'Shaftwfisfcarried by a bearing sleeve.- 3 and extendstherefrom to and .through anotherf bearingzsleevef at the .leftfend off-the work support.

1 Outwardly of the-sleeve 32 thereis secured to theendof the shaft 28 a unit 33- which comprises afeed I. roller and .rotary `:electrode to -be `presently describedin detail. Theunit hasa vcentral sleeve. with an: enlarged, collar-like `head 84 secured to the shaft 28 by means of a set "screw- 35. Ona reduced'l portion 36 ofthe sleevesthere.` is mounted. apair of members 31 and-38 adapted to form a feedA roller having-spacedwork yengaging cylindrical surfaces 39 and. The-members 31and38 are'y preferably .formed of-.a relatively hard and non-yielding materialzhaving'good dielectric properties. They .may suitably be -formed ofa type of silicone rubber .corresponding with ordinary hard Arubber but. having greater resistance to high temperatures. Any other material having similar characteristics Vmay be usedfor theprodliction of these parts. Between the parts 31 and 38 there isclamped a disc-like or-.washerlike element 4| formed of.` asuitable softrubberlike material having good dielectric properties and capable of vwithstanding 4relativelyhigh temperatures up to say` 500 F. It hasbeen found that a. silicone rubber of the typecommercially sold'underthe trade name Silastic type No. 167, .is quite satisfactory forthe purpose. This has yproperties of elasticity and compressibility corresponding with those of ordinary rubber. and, at.l the-.same time, it `is-,capable of Ywithstanding higherV temperatures lwithout deterioration kor injury. It kalso has .a high dielectric constant. Around thefperiphery of the `element 4| there is providedea ring or.band.42 formed Ofmaterial having good electrical conductivity and having high flexibility andv resilience. This .ring may suitably be formed ofan. aluminum bronze alloy and have a wall thickness of, say, .010 of i an inch. Preferably the edges-.of the ring are bevelled at an angle of 45, as shown at .43,andv 44 in Fig- 8, and the bevelled edgesare, in the courseof producing lthe .intermediate or electrode .member of the unit, spun downwardly overthe outer faces of the rubber likeelement 4|. AThe band 42 is arrangedtchave .goodpress 4ilt over the element 4| and is adapted to yieldreadily in response to any radial pressure. .The .resilience of `the band, together with the resilience-and yieldability of the rubber-like element 4I, tends to maintain .the band and element in truly circular formwhenever the radial pressure is released. To retain the .parts 31,38 and.4| in `assembled relation, a nut 45.l is provided, this .cooperating with areduced .threaded end 46. of the central. sleeve. Nut 45 serves to `urge.po.rt.3|l against element 4| and the latter. against partA 31 which, in turn, is urged-against the shoulder provided bythe enlarged portion 34 of the sleeve. Asshown in Fig. 7 the f element 4| preferably ts over a shoulder providedy by a -reduced portion ofthe member 31 and itis of slightly greater 'thickness thanthe length of this .shoulder to. permit it to be squeezed slightly in theassemblyof the parts.

The band 42 `is of slightly greater outside diameter. than the cylindrical -`surfaces 38 and-40. It hasfbeen founddesirableto make thejlatterfabout 1.75 inches `in diameter` and the. band -is .preferably .about 11.0.40"1 greateuin diameter .than .said

surfaces, although it may-.be more or less than this. Depending `upon thefdiameter of the surfaces 39 and 40, the nature of the-work to be donepand possibly other factors, the band may suitably have a diameter ywhich is between .020 and .050" greater than that-fofsaid surfaces. As a result of vthis the band 42 is flattened out slightly at ther point of v*engagement of the unit with the work, as the feed yroller (parts 31 and 38) is urgedaagainst thework in the manner to be explained hereinafter. .This flattening of the band is readily permittedl byits flexibility and by the yielding character ofthe element 4|. It will be noted also (Fig. 7) that asubstantial clearance'is providedbetween the element 4| and the outer portions or parts- 31V and 38.

Cooperating with. the lower unit 33,'which extends upwardly througha suitableopening in "le upperv surface of the work support I0, is a similar unit 41 mounted. above the work support. Unit 41 comprises a pair of relatively rigid and unyielding members- 48 and 49 formed`of dielectric material, such -as hard silicone rubber, and having betweenthemfa yielding, relatively soft, rubber-like element-50,preferably formed of silicone rubber such as that sold under the trade-name Silastic, type No. 167. Surrounding the element 50 is a metal band 5| formed of a good electrical conductor, "such as aluminum bronze, and having suitable .flexibility and resilience, as explained in connection with the band 42. The outer periphery of the band 5| is slightly larger in diameter, say to the extent of 20 to 50 thousandths of an inch, thanthecylindrical peripheral surfaces 52 and 53 ofthe members'48 and 49. The unit 41 comprises a central sleeve or kcollar 54 formed integrally with'a bevel gear 55. To the outer end of the collar 54 there is secured, as by screws 56,:a`disc 51 which serves to clamp the members 48, 49 and 50 against the shoulder -provided by the Vinner surface of the bevel gear 55. The arrangement is such that upon the tightening of the screws 56, the members 48, 49, and 50 will vbe flrmly clamped in placeand will'be caused to turn as a unit with the` bevel gear' 55.

If the collar 54 is made of the vsamediameter as the sleeve portion 36'of the lower unit, the parts-48,49 and 50 may be made identical with the parts 31,38and4l, respectively. However, the collar54 may be of somewhat-greater diameter than the part 36 and, in that event, the opening at the centers of the parts 48 and'49 will be corresponding-ly enlarged. They may, for example, be of thesame diameter as the opening through theelement A50 and the shoulder on the pai-5.48, onrwhich the element 50 is-shown mountedin Fig. 7,may be eliminated.

Itwill be noted that as in the case oi" unit 33, the yielding elementv50 has substantial lateral clearance at its outer portion in relation to the rigid .feed roller-partsflvand 49. This clearance in .both units facilitates the `desired flexing of the bands and the consequent compression and yielding ofthe elements 4| -and 50.

The'unit 41 is mounted upon a stud 58 which projects laterally from a bracket 59 and is secured in the bracket by a setscrew 60. Any suitable means.may be provided for retaining the unit-41 onthe stud 58 for rotation thereon. The latter may, for example, be provided with an enlarged head at its outer end for this purpose. If desired, the bevel gear and its collar 54 may-be provided with a bearing-sleeveor bushing to cooperate withthe stud `.58. ..-Bracketv 59, as best shown in Fig. 6, is secured to the lower end of a rod 6| which extends upwardly through suitable bearings in the head I3 of the frame and may be reciprocated axially therein. A spring 62, surrounding the bar 6|, cooperates at its lower end with a collar 63 secured to the bar and at its upper end with the bottom of an adjustable screw-threaded sleeve 64. The spring thus serves to urge the bar 6| downwardly under a force which may be suitably adjusted. Sleeve 64 may be turned by means of its knurled head 55 (Fig. 2) to vary the tension of the spring 62. Downward movement of the bar 6| by the spring is limited by the engagement of the under surface of a collar 66, secured to the bar, with a knife edge 61 on a washer 68 resting upon the lower bearing for the rod. Collar 66 is so positioned on the bar 6I as to arrest the downward movement of the bar at or about the point at which. the surfaces 52 and 53 on members 43 and 49 are brought into engagement with the surfaces 39 and 40 on members 31 and 38. It is desirable generally to limit the downward movement of the upper unit so that the work feeding surfaces of the rollers are held spaced apart, when no work is present, to the extent of about half the thickness of the work being seamed. Thus if two films of 4 mils thickness are being united, said surfaces should be held about 4 mils apart. The top points of the work feeding surfaces 39 and 40 fall preferably at or slightly above the plane of the work supporting surface of the member I9. When the surfaces 52 and 53 are substantially engaged with the surfaces 39 and 40, the bands 5| and 42 will be in engagement and will have their peripheries, at the point of engagement, flattened so as to provide a surface contact having a length, in a circumferential direction, of between about and 1A of an inch.

A sleeve 69, slidably mounted on the bar 6 I, has an arm 10 (Fig. 2) extending rearwardly and arranged to cooperate with a slot 1| formed in the rear wall of the head I3. To another portion of the sleeve 69 there is secured a link 12 extending downwardly from the free end of a lever 13 which is pivotally mounted at 14 on the overhanging arm l2 of the frame. The opposite end of the lever 13 is connected with the upper end of a vertically extending rod 15, the lower end of which is connected with a rock member 15a (Fig. 4) carried by part lll of the frame below the work supporting surface. This rock member is connected, in a manner well understood in the art, with a foot treadle or knee operated member or other means operable at the will of the operator. It will be understood that downward movement of the rod 15 will rock the lever 13 and lift the link 12 and sleeve 69. The initial upward movement of the sleeve will be idle, but it will then engage the under surface of the collar 63 and raise the latter and the bar 6| against the action of spring 62. This may be done whenever it is desired to introduce a new piece of work between the feeding and electrode units 33 and 41. A spring 16, connected at one end to the lever 13 and at the other end to a point on the frame, serves to rock the lever normally into the position indicated in Fig. 2.

An upwardly and laterally extending arm (Figs. 2 and 7) of the bracket 59 provides a bearing for a vertical shaft 18 carrying at its lower end a bevel pinion 19 arranged to mesh with the bevel gear 15. A collar 80, formed integrally with the bevel pinion 19, is secured by set screw 8| to theshaft 18. A collar 82 (Fig. 2) secured to the shaft 18 above the arm 11 serves to retain the shaft 18 and bevel pinion 19 in fixed axial position in relation to the bracket 59. Shaft 18 is mounted for rotation and axial movement within bearing sleeves 83 and 84 carried by the lower and upper portions of the head I3. As the bracket 59 is raised and lowered, in response either to the upward movement of the bar 6| by the lever 13, in the manner explained, or to the upward and downward movements of the unit 41 as the latter passes over work of varying thickness, the shaft 18 will slide axially within the bearing sleeves 83 and 84. f

Rotation is imparted to the shaft 18 by means of a bevel pinion 85 which has a splined connection with the shaft. Pinion 85 meshes with a bevel gear 86 secured to the end of shaft |1, the latter extending into the head |3 through a bearing sleeve 81 (Fig. 1) in a partition wall between the head and over-hanging arm. Pinion 85 is held against axial movement by the lower end of the bearing sleeve 84 and by cooperation with the bevel gear 85. The shaft 18 therefore slides within the bevel pinion in response to the upward and downward movements of the shaft as explained above. Shaft |1 carries a sprocket 88 which is connected by a chain 89 with a sprocket 99 secured to the lower shaft 28. Thus, shaft |1 partakes of the intermittent, successive increments of movement that are given to the shaft 28 by the one way clutch above described. The arrangement is such that the roller units 33 and 41 are rotated at the same peripheral speeds to advance the work across the work support step by step through successive increments corresponding with the stitch length of a conventional sewing machine. Each movement may be between @le and 5M of an inch, depending upon the adjustment of the ball joint in the slot 24 of the arm 25 of the one-way clutch. Any suitable means, such asv an idler 9|, may be employed for taking up the slack in the chain 89 and maintaining the latter in effective driving relation to the sprockets 88 and 9D.

As best shown in Figs. l and 3, the portion of the frame which encloses the various driving connections between the shaft I5 and the shafts |1 and 28 carries lubricant in a reservoir provided at the bottom and this lubricant is whipped into a spray by the parts which dip into it, thereby effectively lubricating the various surfaces which require lubrication.

The electrical system of the illustrative apparatus may be of any suitable character adapted to convert ordinary electrical current, either A.C. or D.-C., into high frequency electrical energy or oscillations and to deliver this to the two bands 42 and 5|, so as to produce a high frequency eld through the dielectric material passing between these bands. This system and its control means may be of the type disclosed in detail in my pending application, Serial No. 739,073, filed April 3, 1947. For further details as to the construction, arrangement, and operation of the electrical devices, reference may be had to said pending application. Only a brief description of these devices will be given herein.

As best shown in Figs. l, 2 and 4, there is mounted beneath the work supporting surface of the member I8 of the frame a tuning stub 92, the outer tubular conductor of which is preferably provided with a slant cut end 92a as described in said pending application. This effects automatic compensation for varying thicknesses of material?.` it'willfbeundersmodthat-the tubular conductor of the -stubZ/has within-it a coaxial conductor;` the Aprojecting yerlernt which'is indicated at v03 in- Fig.4.^- The "inner conductor and a shorticircuiting-element provided -atthe slantcut'end ofthestub are provided with corresponding'inclinedmfaces: The"projecting end ofwthe conductor 93 has `sec11red"'|:hereto` va carrier 93a having'contact"elementsf94 thereoniarrangedfoto engage the edges ofthe-'exible band- 42 vof Vthc lower unit;A4 Elements 04 'are'A formed preferably of Abronze to' 'provide the-desired "resilience and springiness; The" point4 at which 'the Yband is engaged by the' elements Skis'removed some'disu tanceY from the workengaging `surface so that the flattening. of the'bandf42'," in the manner vhere'- inbefore"explained,A will" not affect the contour of'the'band inthe regionkof the contact'elements. Within the tubular ,conductor 'of the stubl92; and surrounding'theY coaxialA 'conductor is" a slidable sleevee95 (Fig. 431 to which is--connected at-o; one endV `oi xa --two-piece rod 91 provided with an extensible *connection 98between the `sections of the rod and 'having itsopposit'ev end engaged with an eccentric pinY or 'screw'SQi of a suitable control member. The pin 99'is carriedv eccentrically by a shaft journalled inabushing lol' carried by the' worlrsupporting` member." Atitsupper end; the shaft `carries a. control knob |02 which may be Hturned tto alter-the position" of vthey eccentric pin 99 and thereby'cause shifting Vcf-"the sleeve SS'withinthe stub;` This permits-manual tuning of the stub at the commencement of an operation in accordance witll'thenature'and type of material 'tobe seamedi' The end ofthe stubis grounded to th'ework support by `means of'a conductor |03 which may suitably beweldedeor solderedto the outer face of the Vstub and'secured by screws or the like tothe under surface of the work support.` Abrush' or contact 'element|ii4;

formed preferably' of bronze and secured 'toA the upper surface of 'the'work`support, has spring rigers |05 arranged. for yielding engagement'witn the edges ofthe upper'ile'xible bandol `ata suit; able distance'froin *the point "ofengagementof the latter with the Work;

Referring nowV tov 'Fig'. '10," high frequency Yoscillations are generated by'an oscillatorV |06Narranged to receive current vfrom` any suitable source. The oscillations,v preferably having afre-V quency of the orderr of 200 "megacycles, are delivered to the`stub"92and Vcoaxial conductor 93 by lines |01 and ijwhich; it will'beunderstood,"are parts' of a coaxial cable; Shifting of the sleeve 95u provides a variable condenser'eiie'ct, such asindicatedat Iin Fl'g.'10fv The condenser action of "the bands' 42 and 5 |n is "illustrated Yin broken lines at vI I0; By'the means indicated,n a high-frequency eld is created through the dielectric material passingbetween the-electrode bands.

In the operation vof the machinethe sectionsv ing'dueto separatiomot -thevl electrodek elements is suiiiciently brief to cause no' serious objection. It has been' found that 4no harm is "doneto the electrode bands'andthe small4 power loss dueto the engagement "of the bands', withthe power on. is so smallas'not to be objectionable. The action in separatin'gthe electrodes'appears'to be akin' to that resulting from'` the operation of 'a quick'acting circuit breaker.

As the work'sectio'ns are fed' between' the rollers of units 33 andland fare* advanced bythe lat# ter, a high"r frequency eldisgenerated through the dielectric'v material 'so' that the thermoplastic substances 'presented between the' electrodes are rendered adhesivaand' produce a 'bond vbetween the worl'ssections'inrsuccessive increments.' It will` be understood 'that 'power issupplle'd 'to the pulley I6 at thistime to drivetheone-way clutch and 'shafts I1"and'28'." Suchpower' maybe de'- rived from any suitable source,`not"sh'own, such as an electric'motor. Aclutchm'ay'be provided in the connection between the `motor andthe pulley -so that the`latter may be driven at will'. Due to the atteningof the bands'42 and `5|,V and the elongated'contact thus provided'witli' the work,` a parallel condenser eiie'ct is produced which' results ineffective transmission of the high' frequency oscillations and the production oi' a continuous seam; Tlius', is'spite' of `the in'' termittent feeding action', thesearn is uninterrupted.' Also, turning of the workf'by the operator is facilitated during the periods when the feed rollers are' stationary so that relativelysharp curves may be followed in the seaming operation.

While an illustrative form ofV the invention has been disclosed in' considerable' detail, it will be understoodV that "numerous changes may be made in the construction and'arrangement of the various partswithout departingirornY thegen-v eral principle andl scope of the invention. For example, the units 33 and 41""may be formed lof materials other than those'specied'. The bands 42 and -5I may be formed'of anyresilient, flexible material whichis a good'condu'ctor of Velectricity and may be ilexedand Athen restored to its normal cylindrical form; as required. Elements 4 I and 50 "may be formed of any rubberlike material 'which'may be readily compressed and thenrestoredto its initial circular form in response tov th flek'i'ng and restorationfof the electrode bands. This material must also be capableof :withstanding the relatively high temperatures to' which" the Velectrodes `are'subjected without substantial deterioration or change in its characteristics. Parts 3T, 38;40 and V49 may be fo'rmed'oi any material which'has good "electrical resistance and is rigid and'capable of with'-v ters, if appropriate provisions are'made 'for vdriv'-, ing them at the same kperipheral's'peeds orif'only` one unit is positively driven while theY otheris driven frictionally through the work'` structural modifications willjsuggest themselves to those skilled'in the art.' The details of the electrical system may also be varied widelyiri accordance withthe teachingswof lthe, art. Tli

invention is adapted for use with any of the high` frequency, oscillations commonly. employed.A for the purposes indicated.

Other What I claim is: j

l. An electronic seaming machine comprising a work supporting member, a plurality of rotary members adapted to engage the opposite faces of the work, means for driving at least one of said rotary members for advancing the work on said work supporting member, electrodes associated with said rotary members and disposed in a plane adjacent thereto, said electrodes being arranged to engage the opposite faces of the work 1 for delivering high-frequency electrical oscillations thereto, at least one of said electrodes comprising a exible metal ring mounted to yield in a radial direction when subjected to localized inward pressure but held against any appreciable l lateral displacement, means for rotating said ring with the associated rotary member, and means for delivering high frequency electrical oscillations to said electrodes.

2. An electronic seaming machine comprising a work supporting member, a plurality of rotary members adapted to engage the opposite faces of the work, means for driving at least one of said rotary members for advancing the worl;

on said worlr supporting member, electrodes asso'ciated with said rotary members and disposed in a plane adjacent thereto, said electrodes being arranged to engagethe opposite faces of the work for delivering high-frequency electrical oscillations thereto, at least one of said electrodes comg prising a flexible metal ring mounted on one of said rotary members for rotation therewith and arranged to yield in a radial direction when subjected to localized inward pressure but held against any rappreciable lateral displacement, and means for delivering high frequency electrical oscillations to said electrodes.

3. An electronic seaming machine comprising a work supporting member, a plurality of rotary members adapted to engage the opposite faces of the Work, means for driving at least one of said rotary members for advancing the worlr on said work supporting member, electrodes associated with and disposed adjacent said rotary members arranged to engage the opposite faces of the 'Work for delivering high-frequency electrical oscillations thereto, at least one of said electrodes comprising a flexible metal ring mounted lon one of said rotary members for roface, a pair of rollers arranged to engage the opposite faces of flat Work pieces to be united, means for yieldingly urging said rollers together, driving means for rotating at least one of said rollers intermittently through successive small increments, an electrode adjacent each of said rollers and rotatable therewith, said electrodes having flexible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillations therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims.

6. An electronic seaming machine which comprises a member having a work supporting surface, a pair of rollers arranged to engage the opposite faces of flat work pieces to be united, means for yieldingly urging said rollers together, driving means for positively driving both of said rollers, an electrode adjacent each of said rollers and rotatable therewith, said electrodes having flexible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillations therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims.

7. An electronic seaming machine which comprises a member having a work supporting surface, a pair of rollers arranged to engage the opposite faces of flat work pieces to be united, means for yieldingly urging said rollers together, driving means for positively driving both of said rollers intermittently through successive small increments, an electrode adjacent each of said rollers and rotatable therewith, said electrodes having flexible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillatation therewith and arranged to yield in a ra- M dial direction when subjected to localized inward pressure, said ring having an outside diameter slightly greater than that of the rotary member on which it is mounted, and means for delivering high frequency electrical oscillations to said electrodes.

4. An electronic seaming machine which comprises a member having a work supporting surface, a. pair of rollers arranged to engage the opposite faces of flat work pieces to be united,

means for yieldingly urging said rollers together, driving means for rotating at least one of said rollers, an electrode adjacent each of said rollers and rotatable therewith, said electrodes having flexible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillations therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims.

5. An electronic seaming machine which comprises a member having a work supporting surtions therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims.

8. An electronic seaming machine which cornprises a member having a work supporting surface, a pair of rollers arranged to engage the opposite faces of at work pieces to be united, means for yieldingly urging said rollers together, driving means for rotating'at least one of said rollers, an electrode adjacent each of said rollers and rotatable therewith, said electrodes having flexible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillations therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims includingresilient contact elements engaging said rims.

9. A work feeding and electrode unit for an electronic seaming machine which comprises a rigid roller formed of non-conducting material and having spaced circular work engaging faces,

and a flexible band formed of material having,

13 between said spaced faces and arranged to yield in a radial direction when subjected to localized inward pressure, said band having a slightly greater diameter than said faces and being sufficiently rigid to resist any appreciable lateral deection.

10. A work feeding and electrode unit for an electronic seaming machine which comprises a rigid roller formed of non-conducting material, said roller being formed in two parts providing spaced circular work engaging faces, and a flexible band formed of material having good electrical conductivity yieldingly mounted between said spaced faces, said band being mounted on a rubber like core clamped between said parts of the roller to permit said band to yield in a radial direction when subjected to localized inward pressure, and said band having a slightly greater diameter than said faces.

11. An electronic seaming machine which comprises a member having a work supporting surface, a pair of rollers arranged to engage the opposite faces of flat work pieces to be united, means for yieldingly urging said rollers together, driving means for positively driving both of said rollers, one of said rollers being spring urged toward the other and being movable toward and from the latter, an electrode adjacent each of said rollers and rotatable therewith, said elec- 14 trodes having exible, normally circular, metallic rims adapted to engage the opposite faces of the work and transmit high frequency electrical oscillations therethrough, each of said rims being of slightly greater diameter than its associated roller and being arranged to yield in a radial direction when subjected to localized inward pressure, and means for delivering high frequency electrical oscillations to said rims.

WILLARD C. RYKERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,425,123 Quayle Aug. 5. 1947 2,432,412 Hacklander Dec. 9. 1947 2,434,330 Merz Jan. 13, 1948 2,439,918 Auxier Apr. 20, 1948 2,458,059 Christensen et al. Jan. 4, 1949 2,474,977 Hart July 5. 1949 2,476,282 Castellan July 19, 1949 FOREIGN PATENTS Number Country Date 573,518 Great Britain Nov. 23, 1945 

